Texas General Knowledge CDL Practice Test
25 realistic General Knowledge practice questions for Texas CDL applicants. Required for: All CDL applicants (Class A, B, and C). Official test: 50 questions, 40 correct to pass.
Question 1 of 25 · Vehicle Dynamics
Empty trucks:
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A.
Always stop more quickly than loaded trucks
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B.
Have less traction because there is less weight on the drive axles
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C.
Can take curves at higher speeds safely
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D.
Are not affected by wind
Correct answer: B.
Empty trucks have reduced traction on drive axles and require greater stopping distances than loaded trucks.
Question 2 of 25 · Mountain Driving
What are two special conditions where you should downshift?
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A.
Before starting down a hill and before entering a curve
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B.
In the city and at intersections
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C.
On bridges and tunnels
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D.
Whenever traffic slows
Correct answer: A.
Downshift before going down a hill and before entering a curve to maintain control.
Question 3 of 25 · Speed Management
Whenever you double your speed, the impact in a crash is:
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A.
Doubled
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B.
The same
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C.
Four times greater
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D.
Half
Correct answer: C.
Crash energy increases with the square of speed — doubling speed quadruples crash forces.
Question 4 of 25 · Emergency Maneuvers
Which of the following is a sign of tire failure?
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A.
A loud "bang" sound
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B.
Vibration or thumping
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C.
Heavy steering or fishtailing
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D.
All of the above
Correct answer: D.
A bang, vibration, heavy steering, or fishtailing can all indicate tire failure.
Question 5 of 25 · Night Driving
When meeting an oncoming vehicle at night, you should:
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A.
Look directly at the headlights
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B.
Look toward the right side of the road
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C.
Switch to high beams
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D.
Increase speed
Correct answer: B.
Look toward the right side of the road to avoid being blinded by oncoming headlights.
Question 6 of 25 · Adverse Conditions
When a vehicle hydroplanes, the brakes:
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A.
Will work better than usual
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B.
May cause the vehicle to spin
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C.
Should be applied hard
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D.
Cause the engine to stall
Correct answer: B.
Braking on a hydroplaning surface can lock wheels and cause spins. Ease off the throttle instead.
Question 7 of 25 · Emergency Equipment
What three kinds of emergency equipment must you have in your vehicle?
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A.
Spare tire, fuses, and reflective triangles
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B.
Fire extinguisher, spare fuses (if equipped), and warning devices
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C.
First aid kit, water, and flares
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D.
Tool kit, fuel can, and flag
Correct answer: B.
You must have a fire extinguisher, spare electrical fuses (if equipped), and warning devices for stopped vehicles.
Question 8 of 25 · CDL Rules
Refusing a chemical test for alcohol or drugs while operating a CMV will result in:
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A.
A warning
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B.
A 90-day suspension
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C.
CDL disqualification of at least one year
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D.
A simple fine
Correct answer: C.
Refusal is treated the same as testing positive — minimum one-year disqualification.
Question 9 of 25 · Driver Wellness
What should you do when an aggressive driver confronts you?
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A.
Make eye contact and respond
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B.
Try to escape the situation safely and avoid eye contact
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C.
Slow down to teach a lesson
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D.
Speed up and pass
Correct answer: B.
Avoid engagement, give space, do not make eye contact, and report the behavior.
Question 10 of 25 · Basic Control
Which of these is the proper way to hold a steering wheel?
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A.
One hand at 12 o'clock
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B.
Both hands on opposite sides of the wheel
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C.
Both hands on top
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D.
One hand at 6 o'clock
Correct answer: B.
Hold the wheel firmly with both hands placed on opposite sides for full control.
Question 11 of 25 · ABS
ABS:
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A.
Allows you to drive faster
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B.
Lets you brake hard without losing steering control
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C.
Means you don't have to use safe driving techniques
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D.
Eliminates the need to inspect brakes
Correct answer: B.
ABS preserves steering during emergency braking but does not shorten stopping distance.
Question 12 of 25 · Cargo
Which is correct about cargo and weight balance?
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A.
Heavy cargo should always be at the rear
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B.
Cargo should be balanced and secured to prevent shifting
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C.
Side-to-side balance does not matter
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D.
Top-heavy loads improve stability
Correct answer: B.
Cargo must be evenly balanced and well secured. Top-heavy loads increase rollover risk.
Question 13 of 25 · Speed Management
You are driving a vehicle that could safely be driven at 55 mph on an open highway. The traffic is heavy and moving at 35 mph. The safest speed for your vehicle in this traffic is most likely:
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A.
25 mph
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B.
35 mph
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C.
45 mph
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D.
55 mph
Correct answer: B.
You should generally adjust to the speed of surrounding traffic when it is safe to do so.
Question 14 of 25 · Mountain Driving
When driving down a long, steep downgrade, you should:
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A.
Apply the brakes lightly to keep the speed down
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B.
Use a low gear and engine braking with intermittent braking
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C.
Coast in neutral
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D.
Press brakes continuously
Correct answer: B.
Use the appropriate low gear, rely on engine braking, and apply service brakes intermittently to control speed.
Question 15 of 25 · Hazard Awareness
Hazardous conditions exist when there are:
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A.
Pedestrians and bicyclists
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B.
Children and elderly drivers
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C.
Distractions and bad weather
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D.
All of the above
Correct answer: D.
Hazards include other road users, weather, distractions, and changing road surfaces.
Question 16 of 25 · Night Driving
You should use low beam headlights:
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A.
Whenever you can
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B.
Within 500 feet of an oncoming vehicle and 500 feet behind another vehicle
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C.
Only in fog
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D.
On lighted city streets only
Correct answer: B.
Use low beams within 500 feet of oncoming traffic and when following within 500 feet of another vehicle.
Question 17 of 25 · ABS
What does ABS do?
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A.
Helps you stop faster
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B.
Prevents wheels from locking up during hard braking
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C.
Replaces engine brakes
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D.
Eliminates the need for service brakes
Correct answer: B.
Antilock braking systems prevent wheel lockup, helping you maintain steering control during hard braking.
Question 18 of 25 · Speed Management
When approaching a curve, you should:
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A.
Brake while in the curve
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B.
Slow down before entering the curve
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C.
Maintain highway speed
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D.
Use the engine brake throughout
Correct answer: B.
Reduce speed before entering the curve, then accelerate slightly through the curve for stability.
Question 19 of 25 · Inspection
Pre-trip inspection of the vehicle should be done in the same order each time so that you:
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A.
Will look professional to other drivers
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B.
Will learn it well and not skip anything
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C.
Can finish faster
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D.
Pass the test more easily
Correct answer: B.
Following the same order helps prevent missed steps and builds reliable habits.
Question 20 of 25 · Adverse Conditions
Which of the following is true about driving in fog?
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A.
You should always drive with high beams
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B.
Avoid driving in fog if possible
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C.
Use the right edge of the road as a guide rather than the center line
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D.
Both b and c
Correct answer: D.
Avoid driving in fog when possible. If unavoidable, use low beams and the right edge as a guide.
Question 21 of 25 · Hours of Service
How often must a driver complete a written record of duty status?
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A.
Every 8 hours
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B.
Every 12 hours
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C.
Every 24 hours
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D.
Once a week
Correct answer: C.
A daily record of duty status (logbook) must be completed each 24-hour period.
Question 22 of 25 · Driver Wellness
Distracted driving includes:
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A.
Talking on a hand-held cell phone
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B.
Eating
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C.
Reading maps
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D.
All of the above
Correct answer: D.
All of these activities take attention from driving and are forms of distracted driving.
Question 23 of 25 · Speed Management
The total stopping distance of a CDL vehicle includes:
-
A.
Perception, reaction, and braking distance
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B.
Only braking distance
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C.
Following distance and brake lag
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D.
Only the distance traveled while braking
Correct answer: A.
Total stopping distance is the sum of perception distance, reaction distance, brake lag, and braking distance.
Question 24 of 25 · Backing
Which of these statements about backing a heavy vehicle is true?
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A.
Back in a curved path whenever possible
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B.
Avoid backing whenever you can
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C.
Back as quickly as possible
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D.
Use only the right mirror
Correct answer: B.
Avoid backing whenever you can. Park where you will be able to pull forward to leave.
Question 25 of 25 · Inspection
When inspecting your vehicle, the engine should be:
-
A.
Running with the hood open
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B.
Off, with the parking brake set, before starting checks under the hood
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C.
Idling in gear
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D.
Warm but turned off only on hills
Correct answer: B.
Set the parking brake, turn off the engine, and chock the wheels before checking under the hood.
About the General Knowledge Test
The General Knowledge test covers safe vehicle inspection, basic vehicle control, shifting gears, communicating, controlling speed, controlling distance, seeing hazards, distracted driving, aggressive drivers, communicating with other drivers, night driving, driving in fog, winter driving, hot weather driving, mountain driving, driving emergencies, anti-lock braking systems, skid recovery, accident procedures, fires, alcohol and other drugs, hazardous materials awareness, and staying alert and fit to drive. Every commercial driver in the United States must pass this test before any other CDL endorsement can be added.
The Texas Department of Public Safety — Driver License Division administers this knowledge test as part of its commercial driver license program. To earn the CDL General Knowledge on your Texas CDL, you need to score at least 40 out of 50 on the official version.
Topics covered on this practice test
- Speed Management: 4 questions
- Mountain Driving: 2 questions
- Night Driving: 2 questions
- Adverse Conditions: 2 questions
- Driver Wellness: 2 questions
- ABS: 2 questions
- Inspection: 2 questions
- Vehicle Dynamics: 1 question
- Emergency Maneuvers: 1 question
- Emergency Equipment: 1 question
- CDL Rules: 1 question
- Basic Control: 1 question
- Cargo: 1 question
- Hazard Awareness: 1 question
- Hours of Service: 1 question
- Backing: 1 question
How to use this practice test
- Read each question carefully. CDL questions are written precisely — small wording differences matter.
- Click "Show Answers & Explanations" only after answering every question. Don't peek mid-test.
- Read the explanation for every question, even ones you got right. The reasoning is more important than the answer.
- Repeat the test until you score 100%. The questions are deterministic per state, so you can track your improvement over multiple sessions.
- Move on to the other endorsement tests for Texas until you're ready for the official exam.
Tips specific to the General Knowledge test
The General Knowledge test is the foundation of every CDL. Topics include vehicle inspection, basic control, shifting, communicating, controlling speed, controlling space, hazard perception, distracted driving, night driving, fog, winter, hot weather, mountain driving, emergencies, anti-lock brakes, skid recovery, accident procedures, fires, alcohol, hazardous materials awareness, and staying alert. Most failures come from speeding through inspection-related questions; slow down and read carefully.
Other practice tests for Texas